Teaching files are useful in the education of diagnostic
radiologists. In the course of professional training, radiologists must master
a large knowledge base of pictures and develop a method to assess any new,
unknown case against that body of information. Imaging-based medical
specialties have been traditionally under the purview of diagnostic radiology.
However, the practice of diagnostic radiology also includes skilful acquisition
of images, such as performing angiography and barium studies, procedures such
as diagnostic biopsy or therapeutic interventions guided by imaging.
Radiologists also participate in clinical consultation ranging from informal �kerbside�
chats with referring physicians to formal multidisciplinary team therapy
planning conferences. �The bulk of the radiologist�s work however, is based
upon the interpretation of images. This article will only deal with teaching
files and diagnostic interpretation skills, and not address the other (far more
interesting but less defined) skills, nor will it discuss imaging research. [1]

Traditionally, teaching radiology has relied heavily on
exposure to the wide range of abnormal cases of different diseases that are
available during the course of on-job-training rotations through teaching
hospitals. Unfortunately, these abnormal cases are usually hidden among an
equally large number of normal studies. Face-to-face teaching, using these
abnormal images, usually conveys significant information on interpreting the
subtle differences between normal and abnormal, normal mimics of disease, and
differentiating different diseases. Most of these mimics have important
consequences for treatment and prognosis. These �tips and tricks�
tutorial-style encounters are usually part of a larger educational curriculum
where formal teaching/lectures are structured around the twin pillars of
imaging technique and biology. However, as in all other human activity, �face
time� is limited, and access to teachers is limited by their other duties in
administration and research, and there may be few opportunities to discuss
interesting cases that illustrate a useful point. One important means to make
up for this deficit is case-based teaching files.

Radiology Teaching Files

At its most basic, a teaching file comprises one or more medical images with
an important feature that has been created from the radiology
studies of a patient, supplemented by relevant clinical data
and a short write-up on the pathological condition and/or relevant
teaching points (Figure 1). Historically, a simple case-based
teaching file comprised the hardcopy film of the image and an
accompanying scrap of paper containing at the very least, a
correct diagnosis. The amount of information can thus vary from
such �bare-bones� files to a full fledged analysis of the subtleties
and pitfalls of diagnosis backed by strong evidence in the medical
literature, attached for the interested student. The effort
required to produce such teaching files also varies, primarily
dependent on the technical difficulty of duplicating the clinical
image record on to the library film, and the intellectual input
demanded of the student. The student is usually one who has
benefited from face-to-face teaching, and now carries the responsibility
of passing on what he has learnt to future generations.

Figure 1 An example of
a hardcopy radiology teaching files comprising film images
showing the relevant feature, a short write up and (optional)
medical literature. In the background is the “library”
of teaching files – this can be a challenge to catalogue
and maintain.

Often, the problem with teaching files is not so much the creation
of the file but the organisation and preservation of many teaching
files. Libraries of representative teaching files are highly
desirable in radiology teaching programs, but cataloguing and
maintenance of these collections for logical and painless retrieval
can be problematic. Thus, cases are often filed using classification
systems such as the American College of Radiologists (ACR) index
of radiological diagnosis; this has several limitations and
is already outdated in these latter days of increasingly specific
diagnosis using advanced imaging techniques.�

Electronic Teaching File

There are many drawbacks to the hardcopy film libraries,
such as physical degradation, and single copies that can be misplaced. To
overcome these drawbacks and to take advantage of the rich digital information
available in picture archive and communications system (PACS), teaching files
should move into the electronic realm.� Here, the advantages of a computerised
structured format and catalogue can be exploited, and many students can access
knowledge at their own pace (Figure 2).

Figure 2 An example of electronic teaching
files comprising digital images showing the relevant feature,
a short write up and other components of traditional teaching
files in an electronic format.

Our group has previously developed Medical Image Repository
Interface with PACS (MIRIP) [2]: a computer server running a database programme
(plus an image server and a web server) that enables users in a teaching
hospital to create an electronic teaching file from information in PACS. All
images are anonymised, and catalogued according to the ACR index. We also
reported a suite of authoring tools that functions as a stand-alone collection
of electronic teaching files for individuals without hospital PACS [3]. These
formats and methods have been expanded to enable participation in the World
Wide Web (http://www.mirip.org/nmirc.jsp)
[4]. With electronic formatting using XML (extensible markup language) Schema,
the process of creating a structured teaching file can be simplified (Figure 3).
A teaching file can be broken into its component parts, including the clinical
description of the case, the radiology images (captioned by appropriate descriptive
text, Figure 4), a short description of the differential diagnosis and discussion
of the disease. The information for each part of the structured format may be
entered by the user by simply filling in a web-based form (Figure 5). Such a
structured method has the advantage of providing a logical and predictable
style sheet and at the same time allows some flexibility to encompass different
types of images ranging from simple �Aunt Minnies� to complex cases with
studies with multiple modalities and differential diagnosis.

Figure 3 Screen capture of the Singapore
National MIRC (medical image repository center) website. This
contains a database and web server that allows users to create
a structured electronic teaching file in a systematic fashion
using the tabs shown on the left (eg. abstract, history, findings,
imaging features).

Figure 5 Screen capture
of the data entry by form filling and drop-down menus. Free
text can be entered to caption the images (“Case Image
Findings”) and diagnosis (“Diagnostic Coding”).
The appropriate ACR coding index can be selected from a list
(arrow).

The World Wide Web and Beyond: Multimedia and Discussions

As far as we are aware, the MIRIP website (http://www.mirip.org) represents
the first attempt to establish a collection between electronic
teaching files for radiology on the Internet based in Asia.
There are many other sites on the Web (http://www.mypacs.net,
http://rad.usuhs.mil/medpix,
http://www.casimage.com, http://www.auntminnie.com)
that offer a �Case of the Day� type electronic teaching files
[5]. They also offer some excellent review
papers have been published that inform radiologists how they
can avail themselves of these resources [6].�
Many of these sites offer search engines, and some, such as
the Medical Image Repository Center (MIRC) initiative of the
Radiological Society of North America (RSNA) (http://mirc.rsna.org)
(Figure 6), seek to establish a method to allow the global community
of radiologists to share medical images for education and research
purposes [7].

Figure 6 Screen capture
of the search feature of a MIRC (medical image repository
center) website. This allows users to query the worldwide
MIRC websites for keywords (in this case “neoplasm”
and see examples of the positive “hits”, each
hit being an electronic teaching file.

Electronic teaching files are desirable as a first step for
teaching, and the world of digital image-based education has
only just begun to be explored. Multimedia teaching files represent
the first step in the dynamic use of audio as well as moving
graphics on a radiological image [8]. Furthermore,
an image-based discussion forum may be feasible, adding an interactive
dimension to teaching that closer simulates the �face-to-face�
consultative process that is essential in diagnostic radiology.

Conclusion

Teaching files can be useful for education of radiologists
and allied professionals. Face-to-face tutorials for interpretive skills can be
supplemented by electronic teaching files, and these can be greatly enhanced by
combining PACS and the Internet. We hope that radiologists and allied
professionals will participate actively by providing content and expertise for
digital teaching files such as online Asian web initiatives (www.mirip.org). These teaching files may form
the basis for more interesting and sophisticated aspects of radiological
education, such as exploring multimedia education of interpretive and procedural
skills.

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